Under 3 inches and you're set.
One measurement settles whether Steadi fits your can, bottle, or cup. This page exists so you never have to wonder — or guess.
53 mm – 3″
Steadi fits a base between 53 millimeters (about 2 inches — a skinny Red Bull) and 3 inches (76 mm) across. Both ends included: 53 mm on the nose fits, and 3 inches on the nose fits. Outside that window — slimmer or wider — it's honestly not a match.
The fins need at least a slim can's worth of base to close around. Skinnier than that — energy shots, airplane minis — and there isn't enough for them to hold. A floor exists; it just sits below almost everything you'd actually set on a couch.
Cans and bottles slide straight into the collar. Wider cups press in through the flexible fins — up to and including a 3-inch base, which seats as a firm, snug press. Past 3 inches, the fins can't give it a proper hold.
And measure the base — the bottom inch where Steadi holds on — not the widest part of the cup. Tapered tumblers are usually narrower down there than they look.
Type the base measurement.
Widest point across the bottom. Inches or millimeters — the verdict is instant.
Three ways to measure. Pick whichever is within reach.
Straight across the bottom.
Turn the container upside down and lay a ruler flat across the base, edge to edge at the widest point. Anywhere from 53 mm (about 2.1″) up to 3″ — including 3 on the nose — and you're set.
A sticky note and a skinny Red Bull.
A standard Post-it is exactly 3″ wide — that's the ceiling. Stand your cup on one: paper showing on every side means you're under 3″; covering it edge to edge means 3 on the nose — still good. The floor gauge is an 8.4-oz slim can (53 mm exactly): if the base is at least that wide, you've cleared it.
For curves and no ruler nearby.
Wrap string, floss, or a charger cable once around the base, mark where it meets, and measure that length flat. Between about 6.6″ and 9.4″ around (17–24 cm) puts the base inside the window.
Cans and bottles: already answered.
Can bodies are made to industry-standard widths — 53 mm slim, 57 mm sleek, 66 mm classic — and every one of them lands inside the window. So does nearly every drink bottle. The short list that doesn't is right here too.
Cups, tumblers, and everything in between.
Tumbler makers change base sizes between generations, so where sizes vary we say so instead of guessing. When a row says measure to confirm, the ruler is a ten-second referee.
| Container | Base | Verdict |
|---|
≈ means the base varies by generation and size — the number shown is typical, not a promise. Verified rows are containers we've seated in a Steadi ourselves.
Every tricky case we've been asked about.
Right at 3 inches
A 3-inch base is inside the window — expect a firm press through the fins, and that snugness is exactly what holds on. It's just past 3 where the fins stop promising: a touch over, send a photo of the base beside a ruler and you'll get a straight yes or no.
The very slim stuff
Energy shots, airplane minis, probiotic bottles, shot glasses — below the 53 mm floor there isn't enough base for the fins to close around, and we won't pretend otherwise. The good news: the floor sits at slim-can width, so nearly everything you'd actually park on a couch clears it.
“Will it fit over my koozie?”
Measure the koozie's outside, not the can. A thick foam koozie usually pushes the outside past the 3″ ceiling; a slim neoprene sleeve often stays inside it. The simplest move: Steadi rides on the can itself — the koozie slips over the top afterward, or takes the day off.
Tapered bases (the Stanley-style silhouette)
Cupholder-friendly tumblers narrow toward the bottom — that's the part Steadi holds. Measure the bottom inch, not the rim. The fins follow the taper as they close. The 40-oz on the founder's desk wears one full-time.
Cups already wearing a silicone boot
A boot adds width — often about a quarter inch. Measure across the boot; if that lands past the ceiling, pop the boot off and measure the bare base, which usually sits back inside the window. Steadi then does the boot's job and the tip-resisting one.
Handled tumblers and mugs
Steadi lives on the bottom inch; handles live up near the rim. They never meet. The only exception is a handle that runs all the way down to the base — rare, and the ruler settles it like everything else.
Stemmed wine glasses
A thin glass foot isn't a base the fins can hold, and we won't pretend otherwise. Stemless glasses and wine tumblers with bases inside the window work the normal way.
Powder-coat, paint, glass, plastic, condensation
The hold comes from a high-friction flexible sleeve, so the finish doesn't matter — powder-coated steel, painted aluminum, glass, and plastic all seat the same. Sweating cans are business as usual: it's waterproof and wipes clean.
Square bottles, cartons, juice boxes
The fins close in a circle, so square and oval footprints don't seat — whatever their size. If the base isn't round, it isn't a match. No exceptions worth chasing.
On the drinks you actually own.
Every photo below is a real container seated in a real Steadi — no renders, no maybes.
Still not sure? You have two outs.
1. Ask a human before you buy.
Set your cup upside down, lay a ruler across the base, take one photo, and email it to support@getsteadi.com.You'll get a straight yes or no — it's Scott who answers, usually same day.
2. Let the guarantee carry the risk.
Every order has a 30-day, 100% money-back guarantee with free returns — so a wrong guess about fit costs you nothing but the walk to the mailbox. Fewer than 1 in 500 orders comes back; we can afford to be generous.